body {
    margin: 0;
    padding: 0;
}

.login_box {
    width: 300px;
    padding: 40px;
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    background: lightblue;
    color: white;
    border-radius: 20px;
    text-align: center;
}

.input_box {
    border: 0ch;
    background: white;
    display: block;
    margin: 20px auto;
    text-align: center;
}

.beijing{
    width: 100%;
    height: 100%;
}